Intraoperative Ventilation of Morbidly Obese Patients Guided by Transpulmonary Pressure
Bariatric surgery has proven a successful approach in the treatment of morbid obesity and its concomitant diseases such as diabetes mellitus and arterial hypertension. Aiming for optimal management of this challenging patient cohort, tailored concepts directly guided by individual patient physiology may outperform standardized care. Implying esophageal pressure measurement and electrical impedance tomography—increasingly applied monitoring approaches to individually adjust mechanical ventilation in challenging circumstances like acute respiratory distress syndrome (ARDS) and intraabdominal hypertension—we compared our institutions standard ventilator regimen with an individually adjusted positive end expiratory pressure (PEEP) level aiming for a positive transpulmonary pressure (PL) throughout the respiratory cycle.
After obtaining written informed consent, 37 patients scheduled for elective bariatric surgery were studied during mechanical ventilation in reverse Trendelenburg position. Before and after installation of capnoperitoneum, PEEP levels were gradually raised from a standard value of 10 cm H2O until a PL of 0 +/− 1 cm H2O was reached. Changes in ventilation were monitored by electrical impedance tomography (EIT) and arterial blood gases (ABGs) were obtained at the end of surgery and 5 and 60 min after extubation, respectively.
To achieve the goal of a transpulmonary pressure (PL) of 0 cm H2O at end expiration, PEEP levels of 16.7 cm H2O (95% KI 15.6–18.1) before and 23.8 cm H2O (95% KI 19.6–40.4) during capnoperitoneum were necessary. EIT measurements confirmed an optimal PEEP level between 10 and 15 cm H2O before and 20 and 25 cm H2O during capnoperitoneum, respectively. Intra- and postoperative oxygenation did not change significantly.
Patients during laparoscopic bariatric surgery require high levels of PEEP to maintain a positive transpulmonary pressure throughout the respiratory cycle. EIT monitoring allows for non-invasive monitoring of increasing PEEP demand during capnoperitoneum. Individually adjusted PEEP levels did not result in improved postoperative oxygenation.
KeywordsPEEP Transpulmonary pressure Bariatric surgery Anesthesia Morbid obesity
- 4.Dixon JB, Schachter LM, O'Brien PE, et al. Surgical vs conventional therapy for weight loss treatment of obstructive sleep apnea: a randomized controlled trial. JAMA. 308:1142–9.Google Scholar
- 10.Futier E, Constantin JM, Pelosi P, et al. Noninvasive ventilation and alveolar recruitment maneuver improve respiratory function during and after intubation of morbidly obese patients: a randomized controlled study. Anesthesiology. 114:1354–63.Google Scholar
- 16.Sutherasan Y, D’Antini D, Pelosi P. Advances in ventilator-associated lung injury: prevention is the target. Expert Rev Respir Med. 8:233–48.Google Scholar
- 17.Futier E, Pereira B, Jaber S. Intraoperative low-tidal-volume ventilation. N Engl J Med. 369:1862–3.Google Scholar
- 31.Futier E, Constantin JM, Paugam-Burtz C, et al. A trial of intraoperative low-tidal-volume ventilation in abdominal surgery. N Engl J Med. 369:428–37.Google Scholar
- 33.Rodriguez PO, Bonelli I, Setten M, et al. Transpulmonary pressure and gas exchange during decremental PEEP titration in pulmonary ARDS patients. Respir Care. 2012;58:754–63.Google Scholar
- 37.Defresne AA, Hans GA, Goffin PJ, et al. Recruitment of lung volume during surgery neither affects the postoperative spirometry nor the risk of hypoxaemia after laparoscopic gastric bypass in morbidly obese patients: a randomized controlled study. Br J Anaesth. 2014;113(3):501–7.CrossRefPubMedGoogle Scholar